Stamp pad and reserve ink supply therefor



June 20, 19%? c. w. LOFGREN 3,326,180

STAMP PAD AND RESERVE INK SUPPLY THEREFOR Filed Dec. 27, 1965 INVENTOR.

United States Patent O.

3,326,180 STAMP PAD AND RESERVE INK SUPPLY THEREFOR Charles W. Lofgren, Oak Park, Ill., assignor to Sanford Research Company, Bellwood, Ill., a corporation of Illinois Filed Dec. 27, 1963, Ser. No. 333,851 2 Claims. (Cl. 118-264) This invention relates generally to hand printers and more particularly to inking devices for manually manipulated rubber stamps and analogous printing instruments.

In the past, inking devices for hand stamps have comprised a shallow tray closed by a hinged cover and containing a porous pad saturated with ink. After a period of use, the supply of ink in the pad is, of course, depleted; and reinking has heretofore been accomplished by pouring fresh ink directly onto the upper surface of the pad or into an upwardly opening channel formed in the tray at one edge of the pad. The reinking schemes of the prior art thus have required inventorying a separate supply of reserve ink; and as a consequence of the resultant inconvenience, much hand stamping is habitually done with less than an optimum supply of ink in the pad. A comparatively dry stamp pad causes faint and fragmentary impressions which are, in turn, a chief objection to hand stamping operations.

Therefore, an important object of the present invention is to provide a self-reinking stamp pad arrangement.

A more general object of the invention is to provide a new and improved inking device for manually manipulated rubber stamps and analogous printing instruments.

Another object of the invention is to provide an inking device that contains a selectively tapp'able reserve ink supp y- Still another object of the invention is to provide a self-reinking stamp pad arrangementin which reserve ink is metered to the pad each time the stamp is pressed into the pad for inking.

These and other objects and features of the invention will become more apparent from a consideration of the following disclosure,

An inking device in accord with the invention includes both a container having a recess for receiving a stamp pad and a porous, ink-absorbing and ink-transmitting stamp pad situated in the recess of the container. An inking device in accord with the invention additionally includes a reserve ink supply member in the container beneath the porous pad; and this reserve supply member consists of an envelope filled with ink. After the factory supply of ink has been depleted from the porous pad, a common pin or other sharp instrument is thrust through the pad to puncture the reserve supply member, one or more such perforations being made for allowing easy egress of the reserve ink from the supply member to the porous pad for reinking.

In order that the principles of the invention may be readily understood, two embodiments thereof, but to which the application is not to be restricted, are shown in the accompanying drawing wherein:

FIG. 1 is a perspective view of an inking device constructed in accordance with the invention, the stamp pad proper being partially cut away to reveal the underlying reserve supply member and the reserve supply member being partially cut away to show the recess which is formed in the container for receiving the reserve supply member;

FIG. 2 is an enlarged, cross-sectional view taken substantially along the line 22 of FIG. 1;

FIG. 3 is a further enlarged, cross-sectional view illustrating use of a common pin in perforating the reserve supply member;

3,326,180 Patented June 20, 1967 ice FIG. 4 is a view similar to the showing of FIG. 2 but illustrating a modified form of the invention;

FIG. 5 is a perspective view of the base ply used for the reserve supply member of the embodiment of FIG. 4; and

FIG. 6 is an enlarged, fragmentary, cross-sectional view of the inking device of FIG. 4.

Referring now in detail to the drawing, specifically to FIGS. 1 and 2, an inking device indicated generally by the reference numeral 10 is seen to comprise a container 12, a porous pad 14 and a reserve ink supply member 16. The container 12 is made up of -a rectangular, relatively shallow tray 18 and. a cover 20 which is swingably mounted to the tray 18 by a hinge arrangement 22. Conveniently, the tray 18 and the cover 20 are fabricated from a durable, lightweight metal alloy, although certain resinous plastics may also be employed. In compliance with the invention, the tray 18 is provided with a recess 24 for receiving the porous pad 14. In addition, the tray 18 is fashioned with a sub-recess 26 for receiving the reserve ink supply member 16 generally beneath the pad 14. Advantageously, the recess 24 and the sub-recess 26 are of rectangular shape, the sub-recess 26 being centered beneath the recess 24. Furthermore, the sub-recess 26 is of lesser longitudinal and lesser transverse dimension than the recess 24 whereby to define a peripheral shelf 28 surrounding the sub-recess 26. This shelf is employed in supporting the edges of the porous pad 14.

The porous pad 14 defines the inking surface and is advantageously fabricated from felt or microcellular foam rubber. Thus, the pad 14 is both ink-absorbin and inktransmitting. The pad 14 is, of course, saturated with a suitably colored ink at the factory. In addition, the porous pad 14 is shaped to fit snugly into the recess 24 and is arranged to be approximately one-quarter inch thick when the inking device 10 is intended for general oflice use.

In accord with a feature of the invention, the reserve ink supply member 16 includes a top ply 30 and a base ply 32 both of flexible imperforate material, the plies 30 and 32 being} marginally connected and medially spaced to form a cavity 34 therebetween. Resinous plastic films are suit-able elements for the plies 30 and 32; and in such case, the edges of the plies 30 and 32 may be provided with heat seals 36 at the contacting edges whereby to form the desired marginal connections. Suitable resinous plastic films for the plies 30 and 32 are chemically inert and relatively tough in order to resist any corrosive action of the ink which is filled into the cavity 34 and in order to resist rupturing under the force of the stamps which are pressed onto the pad 14. Polyester resinous films and particularly terephthalate resinous films, have proved eminently useful in this regard. The material for ply 30 is selected to be sufficiently thin that it may be readily punctured by a common pin or other similar implement. Ordinarily, the reserve ink supply member 16 is made approximately half as thick as the porous pad 14, the reserve ink supply member 16 being shaped to fit snugly into the recess 26 formed in the tray 18. Before the reserve ink supply member 16 is sealed at the factory, a suitable quantity of ink 38 is filled into the cavity 34.

In compliance with another important feature of the invention, the puncturable material of the top ply 30 is sufiiciently tough and resilient to form valving edges 40. The valving edges 40 are shown in FIG. 3 surrounding an orifice 42 which has been punctured therein, for example, by the point of a common pin 44. A solid line showing has been employed to illustrate the response of the valving edges 40 to puncturing pressure, and a broken line showing has been utilized to represent the self-sealing position after the puncturing implement has been Withdrawn. The valving edges 40 respond to the application of stamping pressure by opening somewhat to meter reserve ink 38 into contact with the pad 14. The described terephthalate resinous films are particularly suitable for use in generating the valving edges. As will be recognized, when the initial charge of ink has been sufilciently depleted from the porous pad 14 to require puncturing of the reserve ink supply member 16, several perforations will be formed in the top ply 30 scattered over the surface thereof.

While a particular embodiment of the invention has been thus far described, it should be understood, of course, that the invention is not limited thereto since many modification may be made. Therefore and in order to enhance the understanding of the invention, a modified embodiment is shown in FIGS. 4-6. Since the embodiment of FIGS. 4-6 is similar in many respects to the embodiment of FIGS. 13, like numerals have been used to designate like parts with the suffix letter a being employed to distinguish those elements associated with the embodiment of FIGS. 4-6. The inking device 1011 of FIGS. 4-6 is particularly characterized by the provision of a reserve ink supply member in which the base ply 32a is fashioned with formations that confront the top ply 30a for use in supporting the porous pad 14a against stamping pressure centrally of the peripheral shelf 28a. Specifically, the base ply 32a is fabricated with parallel disposed, transverse ribs 46 which may advantageously be formed integral with the remainder of the base ply by means of appropriate contouring of the extrusion die that is used in making the film for the base ply. While the top ply 30a and the base ply 32a are marginally connected, the top ply 30a need only touch the ribs 46 at the tops thereof. Thus, the top ply may stretch and work over the ribs 46- and into the channels therebetween upon the application of stamping pressure in order to facilitate metering out the reserve ink 38a after the top ply has been punctured.

The specific examples herein shown and described are to be considered as being primarily illustrative. Various changes beyond those described will, no doubt, occur to those skilled in the art; and such changes are to be understood as forming a part of this invention insofar as they fall within the true spirit and scope of appended claims.

The invention is claimed as follows:

1. An inking device for manually manipulated rubber stamps and analogous printing instruments, comprising: a container having a recess for receiving a stamp pad; a porous, ink-absorbing and ink-transmitting stamp pad in said container; and a reserve ink supply member in said container beneath said pad, including a top ply and a base ply both of which are originally im-perforate, said plies being marginally connected and medially spaced to form a cavity there-between for a reserve quantity of ink, said top ply being of selectively puncturable material whereby to facilitate the release of reserve ink to said pad, one of said plies having spaced formations confronting the other of said plies to support said pad against stamping pressure, at least one of said plies being of flexible material whereby to Work into the channels between said formations under stamping pressure for pumping ink out of said cavity.

2. An inking device according to claim 1 wherein said formations are transverse ribs.

References Cited UNITED STATES PATENTS 939,098 11/1909 Sauer et a1. 118-264 X 2,189,551 2/1940 Mittag 118-265 2,209,914 7/1940 Gerber et al.

2,290,488 7/1942 Munson 118-264 2,695,704 11/1954 McGredy 15-539 X 2,919,642 1/1960 Mooney 101-125 2,961,677 11/1960 Zecchini 15-539 3,012,659 12/1961 Schaar 206-46 3,020,836 2/1962 Palmer et al. 101-125 3,104,988 9/1963 Pasinski 118-268 3,172,356 3/1965 Vosburg 101-125 FOREIGN PATENTS 715,449 Great Britain.

DANIEL BLUM, Primary Examiner. 

1. AN INKING DEVICE FOR MANUALLY MANIPULATED RUBBER STAMPS AND ANALOGOUS PRINTING INSTRUMENTS, COMPRISING: A CONTAINER HAVING A RECESS FOR RECEIVING A STAMP PAD; A POROUS, INK-ABSORBING AND INK-TRANSMITTING STAMP PAD IN SAID CONTAINER; AND A RESERVE INK SUPPLY MEMBER IN SAID CONTAINER BENEATH SAID PAD, INCLUDING A TOP PLY AND A BASE PLY BOTH OF WHICH ARE ORIGINALLY IMPERFORATE, SAID PLIES BEING MARGINALLY CONNECTED AND MEDIALLY SPACED TO FORM A CAVITY THEREBETWEEN FOR A RESERVE QUANTITY OF INK, SAID TOP PLY BEING OF SELECTIVELY PUNCTURABLE MATERIAL WHEREBY TO FACILITATE THE RELEASE OF RESERVE INK TO SAID PAD, ONE OF SAID PLIES HAVING SPACED FORMATIONS CONFRONTING THE OTHER OF SAID PLIES TO SUPPORT SAID PAD AGAINST STAMPING PRESSURE, AT LEAST ONE OF SAID PLIES BEING OF FLEXIBLE MATERIAL WHEREBY TO WORK INTO THE CHANNELS BETWEEN SAID FORMATIONS UNDER STAMPING PRESSURE FOR PUMPING INK OUT OF SAID CAVITY. 